LA Weekly ran a long interview last October with Valerie Plame's husband, former Ambassador Joseph Wilson, called Unfair Game. It has good background on the events leading to the Novak leak and the subsequent investigation. Here's a piece:

When Novak called you before his column ran, did you then know that her identity was going to be revealed?

I assumed that the CIA would be able to advise him that he shouldn't publish her name, which they obviously tried to do. It was when it was first published that I realized they had been unsuccessful in doing that.

What was your reaction then?

My initial reaction was probably unprintable. My second thought was, "Why would somebody leak the name? What is the rational goal of doing that?" I concluded that it was probably to discourage others from coming forward. It was the White House's way of telling others, "If you do a Wilson on us, we'll do this to your wife and your family." It's only recently that a number of [White House sources] who have leaked to the Washington Post have said that it was pure revenge and spite.

Subsequent to the publication of Novak's article there was a second wave of the White House pushing the story, calling the press and saying, "The real story here is Wilson and his wife, it's not the 16 words." I got a call from a journalist who said, "I just got off the phone with Karl Rove, and he said to me, 'Wilson's wife is fair game.'" So even a week after the Novak story, Karl Rove was still thinking it was okay to trash my wife. It was only after I went on NBC and subsequently the Today Show and said this might be illegal that those phone calls stopped.

You've suggested that Rove was behind the original leak.